Elastomeric element valve

ABSTRACT

A fluid control valve having a valve body, a cage, and a flexible elastomeric diaphragm with a formed convolution to fully open the cage opening. An elastomeric diaphragm regulator with a flow diverter in the fluid flow path to reduce fluid flow separation and thereby reduce the required flow recovery area before pressure throttling. A raised knife edge seat located on the cage top in a position of stagnant fluid flow to reduce the build-up of contaminants on the seat. An elastomeric diaphragm regulator with a valve actuator coupled to a guided valve stem attached to the regulator diaphragm.

This is a divisional of U.S. application Ser. No. 08/914,555, filed Aug.19, 1997, now U.S. Pat. No. 5,964,446.

This application claims the benefit of U.S. Provisional ApplicationS/No. 60/024,415, filed Aug. 21, 1996.

This invention relates to fluid control valves and in particular topressure regulators or throttling valves including an elastomericdiaphragm element sealing a regulator orifice for flow control.

BACKGROUND OF THE INVENTION

Fluid control regulators, such as gas pressure regulators are in commonuse in gas pipeline systems to assist in maintaining system pressurewithin acceptable limits. As an example, the primary function of a gaspressure regulator is to match the flow of gas through the regulator tothe demand for gas placed upon the system. Also, the pressure regulatormust maintain the system pressure within acceptable limits.

In one type of such gas pressure regulator, a cage is inserted betweenthe regulator fluid input and output ports with a diaphragm assemblybeing under a spring load to seat against an orifice at the top of thecage. Unreliable fluid sealing has been noted occasionally in thisconfiguration, particularly at low fluid flow conditions.

In some such prior regulators, the diaphragm assembly contains severalelements of complicated structure leading to a larger than desiredregulator package which also is expensive to manufacture. In other suchprior regulators, the diaphragm assembly has been reduced to a minimumof components utilizing a flat plate across the top of the cage and overthe orifice opening. However, in such prior regulators the orifice isnot substantially open and the flow path is obstructed even when thediaphragm is in the fully opened position above the orifice, thusreducing the regulated flow through the regulator. This undesiredconfiguration leads to lower regulator flow capacity than desired.

It is desired therefore to provide a fluid control regulator having adiaphragm assembly which accommodates a high flow capacity in a smallregulator package, and contains few components so as to reducemanufacturing and assembling costs.

SUMMARY OF THE INVENTION

A fluid control regulator including a valve body having a fluid inputand a fluid output and a flow passageway therebetween. A cage element isinserted within the flow passageway and is adapted to permit flowthrough the cage and a top orifice between the regulator fluid input andoutput. A diaphragm assembly is movably mounted above the cage orificeto regulate fluid passing between the regulator input and output.

The diaphragm assembly includes an elastomeric diaphragm ring elementcircular in shape and having a flat central portion bounded by a formedconvolution which in one embodiment is provided by a ridged annulardiaphragm portion being joined together by a concave perimeter. Inanother embodiment the formed convolution is provided by a raisedannular ridge in the diaphragm joining together the flat central portionand a flat mounting perimeter. The elastomeric diaphragm element isformed of a nitrile type material or other such elastomeric material.

In the regulator closed position the flat central portion of thediaphragm extends across the cage top to close the regulator orifice andprevent the flow of fluid through the passageway and through theregulator input and output. In response to regulator operation requiringthe opening of the orifice, the elastomeric diaphragm element isflexibly moved away from the cage top with the concave perimeterswitching to a convex perimeter, or the raised ridge portionstraightening out in the second embodiment, and, in both cases, enablingthe regulator orifice to be fully opened. Providing a full opening ofthe orifice allows the regulator to handle a high capacity of fluidpressure as compared to prior regulator devices of this type.

A diaphragm mounting ring includes an exterior surface matching theannular ridged portion of the diaphragm ring in the seated position. Onthe opposite side of the diaphragm, the regulator bonnet includes adiaphragm mounting flange having an interior surface which is contouredto match the diaphragm ring when the ring is flexed to the fully openposition and the diaphragm concave perimeter has been switched to aconvex perimeter, or the raised annular ridge straightens out.

The improved diaphragm assembly of the present invention is supported atits center with a diaphragm head on one side and a flat diaphragm plateon the other side to provide a seat load through a conventionalplug/spring load configuration in for instance an unloading regulator.The diaphragm head also serves as a flow deflector to prevent diaphragmerosion and to increase capacity. As an alternative, the centerdiaphragm support can be drilled to provide a balancing port for aloading/actuated style regulator to provide a balanced plug curtainstyle valve. Therefore, the pressure regulator with an elastomericdiaphragm assembly of the present invention enables the production of ahigh capacity, small package, in-line maintenance regulator valve thatis adaptable for both loading and unloading actuation.

In a preferred embodiment of the invention, a fluid control valve, suchas a throttling valve, includes a valve body having a fluid inlet, afluid outlet, and a fluid passageway therebetween. A cage memberincludes a cage interior receiving fluid at one cage end and a cap atthe other cage end having cap openings in fluid communication with thecage interior. The cage member is mounted within the valve body fluidpassageway for passing fluid from the valve body fluid inlet through thecage interior, and continuing through the cap openings to exit from thevalve body fluid outlet. A flexible diaphragm is mounted in the valvebody and flexibly movable from adjacent the cap openings to move awayfrom the cap openings in controlling the flow of fluid between the valvebody fluid inlet and the fluid outlet. Flow diverter means within thecage interior reduce the separation of the fluid flow which is passingbetween the cage top end and the cap openings so as to reduce therequired flow recovery area as the fluid flow exits the top cage end andthen enters the cap openings on the way to the valve body fluid outlet.

In one embodiment, the flow diverter means is provided by a decreasingcage interior volume as viewed by the fluid flow progressing from thecage inlet at the bottom of the cage to the cage outlet, and followed bya substantially constant cage interior volume as the flow continues toexit the top of the cage. This decreasing cage interior volume followedby a substantially constant cage interior volume portion tends to makethe fluid flow curve around the top of the cage with a minimum of flowseparation so as to reduce the amount of flow recovery area normallyrequired prior to the fluid entering the cap openings. In anotherembodiment, a flow diverter is provided by a decreasing cage interiorvolume portion as the fluid flow progresses from the bottom of the cagetowards the top of the cage, followed by a ledge projecting into thecage interior and with the projection continuing to the top cage end,either as a sharp ledge or as a more rounded ledge. In either event,this alternative flow diverter reduces the fluid flow separation as thefluid passes out the top cage end and goes towards and finally entersthe cap openings. The ledge can also include a substantially constantcage interior volume in continuing to the top of the cage.

A raised seat is provided on the cage cap and is situated between thecage top end where the fluid flow exits the cage and the cap openings.Preferably, the raised seat is located at a position of low turbulenceand of low velocity, in a stagnant flow region. This enables the sealingof the raised seat by the diaphragm to be more reliable under all flowconditions, including low flow conditions which caused fluid sealingreliability problems in prior regulator valves. In addition, because ofthe flow diverter means reducing flow separation around the throttlingarea, the seat can be efficiently located so as to avoid the loss ofregulator flow capacity which was required in prior devices.Furthermore, the flow diverter means enables the location of a desiredsharp raised seat or knife edge seat in an area on the cage cap so as tosignificantly reduce the build-up of contaminants on the seat.

A retaining ring engages the cap for mounting the cage in the valvebody. The retaining ring can be a hollow ring enabling full fluid flowtherethrough, or can include flow blocking fingers in the ring interiorwhich fingers can mate with the cap openings to desirably reduce theflow capacity of the regulator. In this manner, one cage can be usedwith any number of capacity alternatives by simply changing the retainerring to a respective ring having none or a varying plurality of flowblocking fingers. Alternatively, the retaining ring could beincorporated with the cage in a single casting.

A center diaphragm support is mounted to the diaphragm central portionand includes a lower diaphragm plug-like head and an upper flatdiaphragm plate with the diaphragm central portion sandwichedtherebetween. Aspirator passageways extend through the center diaphragmsupport for communicating the loading chamber on one side of thediaphragm to the other diaphragm side.

In an alternative embodiment, the aforementioned regulator valve mayinclude a noise attenuation device. The noise attenuation device isprovided by a perforated member surrounding the cage and intermediatethe fluid flow progressing from the cap openings to the valve bodyoutlet so as to attenuate noise in the fluid flow. One or more of suchperforated members can be mounted into position surrounding the cage toprovide flow diffusion so as to reduce noise generated by turbulence,depending upon the level of attenuation desired.

A valve stem is engageably coupled to the center of the diaphragm so asto move the diaphragm towards and away from the cap openings, andpassageways in the valve body accommodate and guide the valve stemduring such movement. This guided valve stem configuration permitsstabilizing of the diaphragm. Alternatively, instead of stem guiding,the diaphragm assembly can include a skirt portion movably guided withinthe valve body. A travel indicator having a scale also may be mounted tothe valve body to cooperate with a marker on the valve stem to indicatethe valve stem position and therefore the opening position of the valve.

In a further embodiment of the invention, the valve stem actuateddiaphragm is attached to a conventional valve actuator wherein themoving forces are supplied through a loading pilot. Such a valveactuator and regulator combination in accordance with this invention canbe reliably used for low differential pressure applications. In aself-operated version of the actuator/regulator combination, instead ofthe moving force supplied through a loading pilot, the controlledpressure can be obtained from the downstream pressure.

The present invention solves many of the prior problems encountered inprior regulators using an elastomeric diaphragm and throttling cageelement. In addition, the present invention provides many significantadvantages, including the following:

A. "Plug Style" Elastomeric Regulator

a. A diaphragm mounting plug provides a hard surface on the fluid inletto avoid erosion by absorbing the high energy of particle impingement.

b. The diaphragm plug along with the improved seat of the presentinvention provides longer seat life. The cage seat has a sharp seatingsurface. The cage seat is also provided for seating and not for apressure drop, as the pressure drop is taken else where within thethrottling cage, thus protecting the seat. The improved cage seat incombination with the diaphragm plug, provides longer seat life.

c. The diaphragm plug with the guided valve stem enables the use oflighter weight diaphragms so as to lower the minimum pressuredifferential and reduce hysteresis error, thus improving controlregulation over wider ranges.

d. The diaphragm plug with the guided valve stem provides enhancedregulator stability over a pressure range.

e. The diaphragm mounting assembly enables spring assisted fluidshut-off.

f. Diaphragm mounting assembly enables the formation of a "cupped"diaphragm from a flat sheet, thus reducing the cost of the diaphragm andadding flexibility in the choice of diaphragms.

g. Diaphragm mounting assembly and guided valve stem enables the use ofa true travel indicator and/or with limit switches, etc., for indicatingthe true plug position in an elastomeric element device.

B. Throttling Cage

a. The throttling cage is designed as a direct insert for the controlvalve body to convert the control valve to a regulator or to anelastomeric control valve.

b. The flow diverter structure in the cage provides a "flow dam" forstability and to move the pressure drop region from the raised seat toother area so as to prolong seat life.

c. The desirable sharp or knife edge seat in an elastomeric elementstyle regulator is advantageously combined with the diaphragm plug.

d. The cage retainer also acts as the diaphragm retainer. Also, the cageretainer can be used to selectively reduce flow capacity.

e. The throttling cage has an integral seat. Also, the throttling cagecan be combined with noise attenuating veins and can also incorporate aprimary/secondary seat configuration if desired.

C. Elastomeric Diaphragms

a. The flat diaphragm may be formed into a cupped shape utilizing thediaphragm mounting assembly.

b. A flat diaphragm is easier to manufacture and can be made fromspecial materials, i.e., carboxylated nitrile, viton, and others toenable versatility in applications.

In addition, the fluid control valve of the present invention can be:(1) used in gas or liquids; (2) used as a relief, back pressure,pressure reducing, or flow control valve (via differential on pilot)using a simple change of pilot; (3) can be remotely controlled utilizingthe guided valve stem with appropriate coupling devices; (4) canincorporate a microprocessor controlled pilot; and (5) can incorporatean integral shut-off.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of this invention which are believed to be novel are setforth with particularity in the appended claims. The invention may bebest understood by reference to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals identify like elements in the several figures and in which:

FIG. 1 is a sectional view of a fluid pressure regulator and elastomericdiaphragm assembly in accordance with the present invention withopposite sides of the regulator centerline showing respectiveoperational positions for convenience of illustration;

FIG. 2 is a plan view of the regulator cage of FIG. 1 illustrating thecage top and the cage outlet which is sealed by the diaphragm element;

FIG. 3 is a sectional view of an alternative fluid pressure regulatorand elastomeric diaphragm assembly in accordance with the presentinvention;

FIG. 4 is a plan view of the regulator of FIG. 3 with the valve bonnetremoved to illustrate the cage top;

FIG. 5 is a sectional view of a fluid pressure regulator and elastomericdiaphragm assembly in the preferred embodiment of the present inventionwith opposite sides of the regulator centerline showing respectiveoperational positions for convenience of illustration;

FIG. 6 is a plan view of the regulator cage of FIG. 5 showing thelocation of a raised sharp seat with respect to the cage cap openings;

FIG. 7 is an enlarged fragmentary view of the top of the cage of FIG. 5illustrating the flow diverter and the position of the raised seat;

FIG. 8 is a fragmented sectional view illustrating another embodiment ofa flow diverter;

FIG. 9 is a plan view illustrating a cage retainer ring with flowcapacity fingers mating with the cap openings of the cage in FIG. 6;

FIG. 10 is a sectional view taken along section line 10--10 of FIG. 9;

FIG. 11 is a fragmented view of a regulator in accordance with theinvention including a perforated flow diffusion member surrounding thecage for noise attenuation and with an alternative diaphragm mountingassembly including passageways for aspirating loading chamber pressure;

FIG. 12 is a sectional view taken along section line 12--12 of FIG. 11with the cage eliminated for ease of illustration;

FIG. 13 is a fragmented sectional view illustrating a regulator inaccordance with the present invention including a guided valve stem anda travel indicator indicating the position of the valve stem;

FIG. 14 is a fragmented sectional view illustrating a regulator inaccordance with the present invention with a guided valve stem couplingto a valve actuator and being operated by a pilot control valve; and

FIG. 15 is a fragmented sectional view of an alternative embodimentregulator with a primary seating plug and a secondary seating diaphragm.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate one embodiment of the invention incorporating aunique elastomeric diaphragm assembly in a fluid pressure regulator. Itis to be understood that whereas the specific illustration herein is inconnection with a fluid pressure regulator of the unloading regulatortype, the elastomeric diaphragm element also can be applied to loadingregulator types of fluid pressure regulators.

Turning now to FIGS. 1 and 2, there is illustrated a fluid pressureregulator 10 including a regulator body 12 having a fluid inlet 14, afluid outlet 16, and an interconnecting passageway 18 for communicatingfluid from the inlet 14 through the regulator body 12 and to the outlet16. For convenience in describing the invention, the left-hand side ofthe regulator is illustrated in the closed position, whereas theright-hand side is illustrated in the open position.

Within the passageway 18 in the regulator body 12, there is provided anelongated cage 20 with a bottom end mounted on an annular support shelf22 encircling an aperture 24 which fluidly communicates the inlet 14with a hollow case interior 26 leading to a cage outlet 27. At the topof cage 20 there is provided a cap or end wall 28 having a series ofopenings in the form of open slot apertures 30 which apertures 30together form a passageway for the fluid within the hollow cage interior26 on one side of the cap or cage end wall 28 and the outlet fluid inpassageway 18 on the opposite side of the cage end wall.

An outer edge 32 of the cage end wall 28 rests against an inner surface34 of the regulator body 12 within the passageway 18 in a guideclearance that aids in vertical assembly of the components. The openslot apertures 30 thereby communicate fluid passing through the cageoutlet 27 to the passageway 18 and eventually to the regulator outlet16.

A diaphragm assembly 36 is provided for controlling the flow of fluidthrough the regulator orifice and includes an elastomeric diaphragm 38having a central portion 40 substantially sandwiched between a diaphragmhead 42 supporting the diaphragm on one side and a diaphragm plate 44supporting the diaphragm on the opposite side. A nut 46 threadablymounts to a threaded upright portion of the diaphragm head 42 so as tosecurely maintain the elastomeric diaphragm 38 in position and to securethe components of the diaphragm assembly. The diaphragm plate 44 servesas a spring seat and is larger than the cage outlet 27 to provide asealing of the outlet 27 at regulator lockup.

With reference to FIG. 1, it may be seen that there is illustrated forconvenience on the left side of regulator centerline 48 the position ofthe diaphragm assembly 36 when sealed against a corner seat 29 of thecage end wall 28 to block the cage outlet 27. The portion of the endwall 28 having the open slot apertures 30 supports the diaphragm 38.

On the right side of the centerline 48 there is illustrated the positionof the diaphragm assembly 36 during operation of the regulator to openthe regulator orifice and enable the fluid flow to pass from regulatorinlet 14 through aperture 24, through the hollow cage interior 26 andcage outlet 27 and into the diaphragm chamber 50, through the slotapertures 30 and into the passageway 18, and finally to the fluid outlet16.

The elastomeric diaphragm 38 is preferably formed of nitrile andincludes the flat central portion 40, an annular ridged portion 52, anda concave perimeter 54 joining the ridge 52 and the central portion 40.An outer mounting ring portion 56 is provided for mounting the diaphragmassembly 36 between a diaphragm mounting and cage retaining ring 58 anda diaphragm mounting flange 60 of a regulator bonnet 62. A series ofhold down bolts 64 threadably engage the regulator body 12 for securelymaintaining the bonnet 62 in position with the diaphragm assembly 36therebetween. The cage mounting ring 58 is adapted to hold the cage 20in position so as to form a diaphragm convolution for the requireddiaphragm travel, and to produce a metal/metal contact to carry the boltload that prevents the diaphragm from crushing. If desired in certainregulator applications, the diaphragm 38 as shown herein may be utilizedwith a modification in the shape of the cage retaining ring 58 toprovide a restricted flow capacity as will be described hereinafter withreference to the cage retaining ring of FIGS. 9 and 10. Suitable O-ringsare provided between the bottom of the cage 20 and the support shelf 22as well as between the diaphragm mounting and cage retaining ring 58 andthe regulator body 12 as illustrated.

A spring 66 has one end seated against the bonnet interior and anotherend seated against the diaphragm plate 44. The spring 66 provides a seatload through the diaphragm plate 44 and the sharp corner seat 29 of thecage 20. Typically, in the unloading regulator 10, the spring 66 is setat a spring set pressure so that when the outlet pressure in regulatoroutlet 16 is below the spring set pressure, the diaphragm assembly 36 isin a position shown on the left side of the centerline 48 with thediaphragm 38 seated against the corner seat 29 of the cage end wall 28to close off the regulator orifice. As is well known in the art, a pilotregulator (not shown) senses the outlet pressure at the outlet 16 and isfluidly coupled through the bonnet 62 into a loading chamber 68 on theopposite side of the diaphragm assembly 36 to enable the loadingpressure to exhaust, thereby counteracting the spring 66 and opening theregulator orifice. This enables the inlet pressure at inlet 14 to becoupled to the regulator to the fluid outlet 16 and helps to maintainthe regulation of the outlet pressure.

When the inlet pressure opens the regulator orifice, i.e. in going fromthe closed situation shown at the left-hand side of the centerline 48 inFIG. 1 to the fully opened position shown in the right-hand side of FIG.1 it is desired that a large fluid flow through the regulator can beaccommodated. As can be seen from the right side of the centerline 48 inFIG. 1, in regulator 10, the elastomeric diaphragm ring 38 can flexiblymove outwardly away from the cage end wall 28 to a fully opened positionaffording a large diaphragm chamber 50 which can accommodate a largeflow capacity and thereby enable the regulator to be utilized for awider range of flow applications than with prior devices. In particular,it may be noted that the elastomeric diaphragm ring 38 has a formedconvolution which includes the concave portion 54 at its perimeter sothat when the valve is opened the concave portion 54 becomes convex asshown in the right side of FIG. 1. Thus, a full regulator orificeopening affording a substantially unobstructed flow path is obtainedwith a minimum size elastomeric diaphragm element.

The diaphragm mounting ring 58 includes an inner surface 70 which iscontoured to match the concave portion 54 as well as the annular ridgedportion 52 of the elastomeric diaphragm ring 38 as shown on the leftside of centerline 48. Also, the regulator bonnet 62 includes an insidesurface 72 which is contoured to match the elastomeric diaphragm ring 38as the concave portion 54 switches to become convex upon regulatororifice opening as shown on the right-hand side of the centerline 48 inFIG. 1.

The elastomeric diaphragm assembly of the present invention may also beused in a loading regulator where an actuator can be attached to thediaphragm assembly to move the elastomeric diaphragm ring 38 in order toposition the diaphragm for the required flow as will be described withreference to FIG. 14.

Referring now to FIGS. 3 and 4, there is illustrated an alternativefluid pressure regulator 74 having a regulator body 76 with a fluidinlet 78, fluid outlet 80 and an interconnecting passageway 82.

FIGS. 3 and 4 illustrate a regulator having this similar components asthe regulator shown in FIGS. 1 and 2, i.e., a valve body, a cage mountedin the valve body, and with an elastomeric diaphragm and plug, exceptthat the convolution in the diaphragm element is formed differently.

A cage 84 with apertures in the form of cap openings 86 is mountedwithin the valve body. Elastomeric diaphragm 88 has a perimeter mountingportion 90 trapped between the cage 84 and a valve bonnet 92 mounted onthe valve body. A bead seal 94 acts to maintain the diaphragm within thevalve body and to seal the passageway 82 from the atmosphere.

The diaphragm 88 also includes a formed convolution provided by a raisedannular ridge 96 between the mounting perimeter 90 and a centraldiaphragm portion 98. The raised annular ridge 96 straightens as thediaphragm is moved away from the cage top so as to flex to a fullopening position adjacent inside surface 100 of the valve bonnet 92 inthe same manner as the concave/convex diaphragm of FIG. 1.

The regulator 74 also includes a diaphragm mounting assembly including alower diaphragm head 102 and an upper diaphragm plate 104 with thecentral diaphragm portion 98 sandwiched therebetween. As can be seenfrom FIG. 4, the upper diaphragm plate 104 includes an annular skirt 106movable between a guide surface 108 in the bonnet 92 such that there isprovided a skirt guided movement of the diaphragm. A control spring 110functions in the same manner as the control spring 66 of FIG. 1. Also,the cage 84 includes a corner seat 112 which cooperates with thediaphragm 98 to shut off the flow of fluid from the inlet 78 to theoutlet 80.

FIGS. 5-7 illustrate a preferred embodiment of a fluid control valvewith an elastomeric diaphragm element in accordance with the presentinvention. In the illustrated regulator 114 there is provided aregulator body 116, having a fluid inlet 118, a fluid outlet 120, and aninterconnecting passageway 122. An elongated cage 124 is inserted withinthe passageway and includes a hollow cage interior 126 leading to a cageoutlet top edge 128 at the cage top as shown in FIG. 5. A cap portion130 at the top end of the cage has a series of cap openings 132 in theform of slot-like apertures which extend through the cap 130 so as tocommunicate fluid from inlet 118 through the cage interior 126 and outthe cage outlet top edge 128 and into the passageway 122 leading to thefluid outlet 120.

The cage 124 also includes a raised annular seat 134 on the cap 130. Asshown in FIG. 7, the raised annular seat 134 is in the form of a knifeedge to provide a sharp seat and is located on the cap 130 at a positionwhich is intermediate the cage outlet top edge 128 and the cap openings132. In connection with the embodiment of FIGS. 5-7 a flow diverterconfiguration has been included in this embodiment so as to enable theseat 134 to be desirably located at a position on the cap 130 which is aregion of low turbulence or low velocity i.e., a basically stagnant flowregion.

In particular, it may be noted from FIGS. 5 and 7 that the cage 124includes a lower interior portion 136 of reducing diameter from the cagebottom at 138 to a cage interior area 140. The following cage interiorupper portion 142 extending from the area 140 to the cage outlet topedge 128 has a substantially constant diameter. In this configurationthe cage interior lower portion 136 and the cage interior upper portion142 tends to reduce the separation of the fluid flow passing from thecage interior around the cage outlet top edge and on the way to the capopenings. Accordingly, this flow diverter structure enables a moreefficient recovery of the fluid flow exiting the top of the cage andbefore entering the cap openings 132, thereby leading to betterregulator stability, particularly at low flow conditions. In addition,the flow diverter enables the desired raised sharp seat 134 to belocated at an area of low velocity and turbulence thereby significantlyreducing the build-up of contaminants on the seat and seat erosion, andwithout the need to provide a longer recovery area which decreases theflow capacity as required in prior regulators attempting to solve thisproblem.

As can be seen from FIGS. 5 and 7, the top surface of cap portion 130 ofthe cage 124 is in a frustoconical shape. Thus, instead of utilizing aformed convolution in the diaphragm element to obtain a full cage outletopening, a flat elastomeric diaphragm element 144 is provided. The flatdiaphragm 144 is mounted between a lower plug-like diaphragm head 146and an upper diaphragm plate 148 in a similar manner as described inconnection with FIG. 1. The perimeter edge portion of the upperdiaphragm plate 148 is sized with respect to the raised sharp seat 134such that in the closed regulator position shown to the left side ofcenterline 150 in FIG. 5, there is a reliable seating pressure tosecurely seat the diaphragm 144 onto the raised sharp seat 134. A spring152 performs the same function as the spring 66 described in connectionwith FIG. 1. The plug-like diaphragm head 146 prevents an undesiredimpingement of particles in the flow stream onto the diaphragm 144 anddeflects the flow away from the diaphragm in a manner similar to theembodiments of FIGS. 1, 2 and 3, 4.

FIG. 8 illustrates a cage 154 having an alternative flow diverter. Aprojecting ledge 156 protrudes into the cage interior 158. A cageinterior lower portion 160 decreases in diameter. A cage interior upperportion 162 remains substantially constant in diameter from the ledge156 to the cage top edge 164. This flow diverter configuration alsotends to reduce the flow separation of the fluid as the fluid passesfrom the cage interior 158 past the cage outlet top edge 164 and to thecap openings 166 to provide the resulting advantages previouslydescribed in connection with FIGS. 5-7. It is to be understood thatrather than the constant diameter section 162, this cage portion can becurved from ledge 156 to the cage outlet top edge 164. Also, instead ofthe sharp right angle ledge 156, a more rounded ledge can also beutilized to provide the desired flow diversion to reduce flow separationbeyond top edge 164.

A cage retainer 167 is provided for mounting within a ledge in the valvebody and maintaining the cage 124 securely in position. Retainer ring167 also includes a suitable groove for receiving a downward turnedperimeter lip of diaphragm 144 (see FIG. 5). Mounting the valve bonneton the valve body securely maintains the diaphragm, retainer ring andcage in position. Initially, with the diaphragm 144 mounted between thediaphragm head 146 and the plate 148, the elastomeric diaphragmperimeter lip is fitted within the retainer ring. The diaphragm 144 liesflat on the cap portion 130 in a frustoconical shape as shown on theleft side of the center line 150 of FIG. 5. Accordingly, the diaphragmis initially flat and when mounted onto the cage adapts to thefrustonconical shape of the cap portion 130 as shown in FIG. 5. Also,when the diaphragm is moved away from the cap openings, the diaphragmcan flex upwardly to assume a fully open position against an insidesurface of the bonnet as illustrated on the right side of center line150 in FIG. 5.

FIGS. 9 and 10 illustrate an alternative cage retainment ring 168 whichincludes a plurality of fingers 170 extending radially inwardly from anannular base portion 172. The fingers 170 are adapted to respectivelymate and fit within the cap openings 132 of the cage 124 shown in FIG.6. Thus, for instance, if a full capacity regulator 114 is desired, theretainer ring 167 having a hollow center is used. If then for instance a50% reduction in flow capacity is desired for the regulator 114, cageretainer ring 167 is removed and replaced with the retaining ring 168such that the fingers 170 inserted into at least some of the capopenings 132 will reduce the flow capacity of the regulator. This is anadvantageous feature when one desires to change the flow capacity of aregulator, in that in prior regulators, several different cages had tobe stocked with a respective flow capacity. The prior cage would beremoved and replaced with a new cage having the desired flow capacity.

In accordance with the present invention, only a new cage retaining ring168 having the desired flow capacity needs to be used. Therefore, thisonly necessitates stocking different flow capacity retainer rings 168instead of entirely different cages, and without having to remove thecage from the valve body to change the flow capacity.

FIGS. 11 and 12 illustrate a regulator containing many of the samecomponents as in the regulator 114 of FIG. 5 according to the presentinvention, i.e., cage 124, diaphragm 144, and the valve body 116. Inaddition, a perforated cylindrical member 174 is mounted so as tosurround the cage 124 from the cap 130 down to the bottom of the cage124. Apertures 176 in the cylindrical member 174 enable fluid to passthrough the member 174. Accordingly, fluid passing from cage interior126 on the upstream side passes through the cap openings 132 and theapertures 176 into passageway 122 and finally to the valve outlet 120 onthe downstream side. This provides a flow diffuser to reduce noisegenerated by turbulence. One or more of the perforated cylindricalmembers 176 can be mounted around the cage 124 depending on the level ofattenuation desired.

With reference to FIG. 11, a lower plug-like diaphragm head 178 includesconnecting passageways 180 and 182. Passageway 182 extendslongitudinally of the centerline 150 and passageway 180 extendshorizontally within the diaphragm head 178 so as to intersect with thepassageway 182 as shown in FIG. 11. Accordingly, a loading chamber 184located above the diaphragm 144 is communicated through passageways 182and 180 to the cage interior 126. Accordingly, when the diaphragm isbeing moved from the closed to the open position, the loading chamberpressure in chamber 184 can be removed by being aspirated throughpassageways 182, 180 to the cage interior 126, so as to enable fasteroperation of the diaphragm and therefore a quicker regulator responsetime. This aspirator technique is, of course, useful for all of theembodiments of the present invention.

FIG. 13 illustrates the incorporation of a travel indicator 186 in theregulator 114 of FIG. 5. Regulator 114 includes a valve stem 188 mountedwithin the diaphragm mounting assembly. The other portion of valve stem188 is slidably captured within a guide piece 190 which in turn isthreadably engaged within the bonnet 165. Thus, as the diaphragm 144moves in position, the valve stem 188 is guided within the guide piece190.

At the top of the valve stem 188 there is provided a marker 192.Position indicators 194 are provided on a scale member 196 which isthreadably engaged within the guide piece 190, such that the scales 194are adjacent and cooperative with the marker 192 on the valve stem.Thus, the travel position of the elastomeric diaphragm 144 from theclosed to the open position is indicated by the travel indicator 186 bythe position of marker 192 with respect to the scales 194. Also, withthe guided valve stem 188 shown in FIG. 13, one could utilize suitablelimit switches, microswitches, proximity switches, or other microsensingdevices to provide electronic sensing and indication of the valveposition.

FIG. 14 illustrates the regulator 114 of FIG. 5 with a guided valve stem198 being guided by a guide piece 200 threadably engaging the bonnet165. A valve actuator 202 is mechanically coupled to the guided valvestem 198 so as to mechanically actuate the elastomeric diaphragm element144 toward and away from the cage cap openings 132. An actuating forceis supplied through a loading pilot 203 and via a loading pressure 204to actuator inlet 206. This actuator system could be used for lowdifferential pressure applications.

As an alternative, the regulator 114 may be used with a valve actuatorin a self-operated regulator configuration using a control spring toobtain desired control pressure settings.

FIG. 15 shows a secondary seat configuration provided for the regulator114. The lower plug-like diaphragm head 146 includes a resilient annularsealing member, such as an O-ring 210 which is suitably mounted within agroove in the diaphragm head. The O-ring is slightly larger in diameterthan the interior diameter of the cage 124. Thus, as the diaphragm head146 is lowered towards the top of cage 124, the O-ring 210 sealinglyengages the cage interior upper portion 162 at an annular seat 212. Thisprovides a primary shut-off for the regulator.

A secondary shut-off is provided by the previously described seatingengagement of elastomeric diaphragm 144 at the raised sharp seat in thecap portion of cage 124. The use of a primary and secondary seat aidsthe reliable shut-off of the regulator and also reduces the seat loadrequired from the regulator spring. In certain circumstances, theelastomeric diaphragm element would not be required to provide anyshut-off so that only the O-ring seat 212 would be needed.

To preform a flat elastomeric diaphragm element into the desiredfrustoconical shape, the flat diaphragm could be trapped between twocontoured retainers such as a lower diaphragm head and an upperdiaphragm plate to deflect the diaphragm element to the desiredconfiguration. In this case, the diaphragm retainers would be suitablycontoured to form the flat diaphragm to the shape desired. Thistechnique would eliminate the need for any special molded parts and alsoincreases the elastomeric compounds which can be used for the diaphragmelement.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

What is claimed is:
 1. A fluid control valve comprising:a valve bodyhaving a fluid inlet, a fluid outlet, and a fluid passagewaytherebetween; a cage member having a cage interior for receiving fluidat one cage end and a cap at the other cage end having cap openings influid communication with said cage interior; said cage member mountedwithin said valve body fluid passageway for passing fluid from saidvalve body fluid inlet through said cage interior, continuing throughsaid cap openings to said valve body fluid outlet; a flexible diaphragmmounted in said valve body and flexibly movable from adjacent said capopenings to away from said cap openings in controlling the flow of fluidbetween said valve body fluid inlet and fluid outlet; and said flexiblediaphragm including a formed concave portion around the entire perimeterof said diaphragm, said formed concave portion straightening andbecoming a convex portion around said perimeter as said flexiblediaphragm is moved away from said cap openings to flex said diaphragm toa substantially dome-shaped fully open position away from said capopenings to increase the fluid flow capacity of said valve.
 2. A fluidcontrol valve according to claim 1, said cage further including a ringseat formed in said cap, and wherein said flexible diaphragm seals saidseat when adjacent said cap openings and unseals said seat when movedaway from said cap openings.
 3. A fluid control valve according to claim2, including a diaphragm center mounting assembly, and wherein saiddiaphragm includes a central portion mounted within said diaphragmcenter mounting assembly, said diaphragm center mounting assemblyincluding a diaphragm plate and spring means for urging said diaphragmplate to seat said diaphragm on said ring seat.
 4. A fluid control valveaccording to claim 1, wherein said formed concave portion is in the formof a formed cone perimeter portion which becomes said convex perimeterportion as the flexible diaphragm is moved to the valve open position.